I am developing in Groovy and I am trying to write a Spock unit test for the following use of Spring's RestTemplate...
Included are my request callback and response extractors, and my initialization class of the RestTemplate bean. I am using the ResponseExtractor to stream the response from GET myurl/ and copy it to a file. The RequestCallback is simply setting some headers on the request.
class RestTemplateConfig() {
@Bean(name = 'myRestTemplate')
RestTemplate getMyRestTemplate() {
RestTemplate restTemplate = new RestTemplateBuilder().build()
return restTemplate
}
}
class MyClass() {
@Autowired
@Qualifier('myRestTemplate')
RestTemplate restTemplate
File getFile() {
ResponseExtractor<Void> responseExtractor = { ClientHttpResponse response ->
// do something with the response
// in this case, the response is an input stream so we copy the input stream to a file
myFile = response.getBody() // roughly, in a psuedocode-ish way
return null
}
RequestCallback requestCallback = { ClientHttpRequest request ->
request.getHeaders().setAccept([MediaType.APPLICATION_JSON])
}
File myFile
// get my file data
restTemplate.execute('myurl/', HttpMethod.GET, requestCallback, responseExtractor)
return myFile
}
}
Spring framework docs for that particular execute(...) method: https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/web/client/RestTemplate.html#execute-java.net.URI-org.springframework.http.HttpMethod-org.springframework.web.client.RequestCallback-org.springframework.web.client.ResponseExtractor-
How do I mock out what's happening in these closures? Specifically, I'm interested in mocking out my response extractor because my current test always returns myFile as null.
when:
// do stuff
then:
1 * restTemplate.execute('myurl/, HttpMethod.GET, _, _) // how can I mock out the expected response here?
0 * _
myFile != null // this fails because myFile is null
